.zippy {
  border: 1px solid black;
  display: inline-block;
  width: 250px;
}
.zippy.opened > .title:before { content: '▼ '; }
.zippy.opened > .body { display: block; }
.zippy.closed > .title:before { content: '► '; }
.zippy.closed > .body { display: none; }
.zippy > .title {
  background-color: black;
  color: white;
  padding: .1em .3em;
  cursor: pointer;
}
.zippy > .body {
  padding: .1em .3em;
}